<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>类选择器</title>
    <style>
        .red {
            color: red;
        }
        .purple {
            color: purple;
        }
        .pink {
            color: pink;
        }
    </style>
</head>
<body>
    <ul>
        <li class="red">玫瑰花</li>
        <li class="purple">紫罗兰</li>
        <li class="pink">桃花</li>
    </ul>
</body>
</html>